This is a quote from SME from an internal post with similar question - hope this is helpful:
PegaCALL provides Genesys integration. Note that this is to the Genesys CTI server (T-Server). iWS is Genesys' desktop - we do not integrate at the desktop level. Indeed, what we provide overlaps and possibly replaces iWS capability. If they wish to continue to use iWS, our integration can complement that - i.e. they can use iWS for telephony control and agent state management while getting screenpops into CPM using PegaCALL.